Synthesis of oxygenated organic compounds



Nov. 2l, 1950 P. T. PARKER y A 2,530,989

SYNTHESIS op oxYGENATEn oRGANxrc COMPOUNDS v Fild June 5, 1947 f Panca-rb YVEA/7' To ALcaHoL Rcovgnv I Puy/'OMM' Patented Nov. 2l, 1950 SYNTHESIS F OXYGENATED ORGANIC COMPOUNDS Paul T. Parker, Baton Rouge, La., assgnor to l Standard Oil Development-Company, a corporation of Delaware Application June 5, 1947, Serial No. l'152,800

9 Claims. (Cl. 26o-632) The present invention relates to the production of oxygenated organic compounds by the reaction of olefins with hydrogen and carbon monoxide and more specifically to means for improving oleiin utilization in processes of this type.

It is well known in the art that oxygenated organic compounds may be synthesized from olens or dioleiins by a reaction with carbon monoxide and hydrogenl in the presence of catalysts containing cobalt, iron, nickel, or the like in a twostep process in which predominantly aldehydes and ketones and minor proportions of alcohols are formed in a iirst-stage in the presence of the catalysts mentioned above and the product from the first step is hydrogenated in a second step to convert aldehydes and ketones into the corresponding alcohols. The catalyst used in the rst stage may be employed in the second stage. However, other known hydrogenation catalysts may be used in the latter stage such as metallic nickel, nickel .supported on kieselguhr. and others. The catalyst for the first stage usually contains promoters such as thoria, magnesia and the like.

The alcohols produced by this process normally contain one more carbon atom than the olefin used as the starting material, the position of the added hydoxyl group depending .on the position of the double bond in the olefin. The olens to be used as starting material may therefore be selected as aV function of the purpose for which the product alcohol is desired.

For example, a detergent such as sodium lauryl sulfate may be prepared from an oleiinic such as undecene-l by the alcohol synthesis. Other oleiins and diolefns such as ethylene, propylene, butylene, pentenes, hexenes, butadiene, pentadienes, olefin polymers such as diisobutylene, triisobutylene, polypropylenes and olenic fractions from the hydrocarbon synthesis process, thermal or catalytic cracking operations, and other sources may be used as starting material depending on the nature of the aldehydes and alcohols desired. The olefins fed may comprise pure oleilns or hydrocarbon mixtures containing olefins. In general, olefins having from 2 to -10 carbon atoms and, more particularly, from 8 to 18 carbon atoms in the molecule are preferred.

The synthesis gas mixture containing hydrogen and carbon monoxide may be produced from any conventional sources such as carbonaceous solids or gases in any manner known per se and in any desired ratio of hydrogen to carbon monoxide. Ratios of 0.5 volume of hydrogen to 4.0 volumes of hydrogen per volume of carbon monoxide may be employed, about 1.0 Volume of hy- 2 drogen per -volume of carbon monoxide being preferred. The reaction of the olens with Hz and CO is generally conducted at pressures in the range of about to 300 atmospheres and temperatures in the range of about F. to 450 F.

The quantity of Hz-l-CO with respect to olefins used may vary within Wide ranges, for example from 1000 vto 45,000 cu. ft. of Hz-i-CO per barrel of oleiin feed. In general, approximately 2500 to 15,000 cu. ft. of Hz-l-CO per barrel of olen feed are employed. In the hydrogenation step temperatures are generally within the range of from about 150 F. to 450 F. while pressures Within the range of about 100 to 300 atmospheres are suitable.

The catalysts for the first stage of the process are usually employed in the form of soaps of the catalytically active metal with high molecular weight fatty acids such as stearic, palmitic, oleic, naphthenic, linoleic, and similar acids of natural or synthetic arigin. For example, metal soaps such as cobalt stearate, nickel oleate, cobalt naphthenate and iron linoleate are suitable catalysts. 'I'hese salts are soluble in the liquid olen feed and may be supplied to the reaction zone in the form of hydrocarbon solutions or dissolved in the olen feed.

In the conventional operation of this process, it has been customary to pass the total oxygenated product from the iirst "stage together with unreacted olefins to the second stage wherein it is hydrogenated. The uneonverted olefins are thus hydrogenated in the second stage to form saturated hydrocarbons Which are of little value and which constitute a loss in the economics of the process. The present invention has for its principal object to provide means for an economic utilization in the process, of olefins which remain unreacted in a single pass through the first stage of the process.

. In accordance with the present invention, this object may be accomplished by subjecting the total product from the oxygenation stage of the process to a distillation treatment adapted to separate unreacted olefins from oxygenated products and recycling the olefins so separated to the oxygenation sta y e.

Experiments "have demonstrated that special care must be taken during the distillation treatment to prevent excessive condensation of desirable aldehydes, which may lead to an excessively -high -percentage of undesirable heavy bottoms in the hydrogenation product. According to the invention such aldehyde condensation may be substantially suppressed or completely prevented 'by carrying out the distillation ci' the total oxytained at a reduced pressure within the range just speciiied. In this manner the sensible heat of the liquid product from the oxygenation stage is utilized for distilling or ilashing the olens. The oxygenated constituents may thereafter be passed on to a conventional hydrogenation stage while the separated olens are recycled to the oxygenation stage.

The invention will be best understood from the following detailed description read with reference to the accompanying drawing, the single gure of which illustrates schematically a system suitable for carrying out a. preferred embodiment of the invention.

Referring now to the drawing, a mixture of feed olens and dissolved oxygenation catalyst is supplied from line I by compressor 3 through line 5 to oxygenation reactor I0. The oleiins which may be obtained from any conventional source may have a boiling range of, say. about 100 to 500 F.. preferably not substantially below 150 F. While any conventional oxygenation catalyst may be used. it has been found that good results may be obtained when employing soaps of iron, cobalt and nickel with high molecular weight fatty acids produced by the catalytic hydrocarbon synthesis from carbon monoxide and hydrogen.

Hydrocarbon synthesis products, especially those boiling above 300 F., contain from 5 per cent to l0 percent or more acids which are extractible with caustic solutions. Experimental work has shown that particularly the cobalt salts of these acids are eflective catalysts for the synthesis oi oxygenated materials from oleins and synthesis gas. This is illustrated by the following experiments. y

Thirty-live grams of the acids extracted from a 350 to 400 F. cut of hydrocarbon synthesis product were neutralized with a solution of 8 0 grams NaOH in 600 cc. of hot water. To this solution were added 100 cc. of an aqueous solution of 24 grams hydrated cobaltous chloride. The mixture was digested for two hours on a hot plate, washed with hot water. and the gummy precipitate dried in a vacuum oven.

A solution of 3.6 grams of cobalt salt prepared as described above was dissolved in a mixture of 360 grams of diisobutylene and 14.4 grams C9 alcohols. The solution was treated for ve hours at 3000 pounds per square inch synthesis gas pressure and a temperature of 300 F. Distillation of the product formed showed 79 per cent of the diisobutylene was converted to ongenated material.

Returning now to the drawing, the liquid oleilns in reactor i0 containing .about 0.05 to 0.5 per cent of active metal component of an oxygenaticn catalyst are passed downwardly and countercurrently to synthesis gas supplied to the bottom of reactor i0 by compressor i2 through line i0 at a pressure of about 3000 pounds per square inch. The ratio of HazCO in the synthesis gas is preferably maintained at about 1:1 and the synthesis gas is supplied at asubstantial excess over that theoretically required for the conversion of the oleiins. This excess may amount to about three to thirty times the theoretical amount. Reactor I0 is preferably maintained at a temperature of about 250 to 400 F. Unconverted synthesis gas is withdrawn overhead from reactor l0 through line I 6 and may be recycled through line i8 to synthesis feed gas line Il and from there to reactor I0. Inert constituents may be purged from line I6 through lines 20 and 22.

The liquid reaction product containing some gas dissolved and/or suspended is withdrawn from a lower portion of reactor i 0 through line 2l and passed to a separator 26 wherein gases are separated from the liquid product. Separated gases may be withdrawn from separator 2B through line 28 and returned to reactor I 0 through line i8. Undesirable gas constituen may be purged through line 22.

The liquid product in separator 26 which is still substantially at the temperature andl pressure of reactor i0 is withdrawn through line 2! and flashed into the low pressure vacuum' still 30. At the oxygenation conditions indicated above, still 30 may be operated at a suitable pressure within the range of about 5 to 500 mm. Hg and a temperature just high enough to flash oil' unconverted olens. Under these conditions unconverted olens may be taken overhead from still 30 through line 32. The olenic overhead is condensed in cooler 34 and returned through line 36 to oleiin feed line I and from there via compressor 3 and line 5 to reactor I0. In this manner the oleiinic feed may be substantially completely converted into oxygenated compounds of a relatively higher boiling range while aldehyde condensation in still 30 is substantially avoidedv The portions of the system described above comprise the essential novel elements of the present invention. 'The remaining portions of the system are essentially standard equipment which may ce operated in any conventional manner. A brief outline of a typical method of operation will be given below.

liquid oxygenated products are withdrawn from the bottom of still 30 and passed through line 38 to a catalyst removal zone 50 which is packed with a catalytically inert solid material such as pumice, ceramic packing, silica gel, alumina. etc. Hydrogen recovered from a later stage of the process, as will'appear hereinafter, may be supplied to zone 50 through line 52 and passed through zone 50 countercurrently to the liquid oxygenated product. Catalyst removal zone 50 is preferably maintained at a temperature of about 200 to 400 F. at which the catalyst which enters zone 50 predominantly in the form of metal carbonyl is decomposed to metal and carbon monoxide. The metal is deposited on the inert packing within zone 50 while the carbon monoxide is purged by the hydrogen. A mixture of hydrogen and carbon monoxide is Withdrawn through line 5d either to be discarded through line 56 or to be passed through line 58 to a methanizer 60 wherein it is converted thermally or catalyticaliy into methane in any conventional manner. The hydrogen-methane mixture may be passed through line 62 to hydrogenation reactor 65. i

The liquid oxygenated product now free of oxygenation catalyst is withdrawn from zone 50 through line 64 and passed to a top portion of hydrogenation reactor 65. Simultaneously, hydrogen is supplied to reactor 65 through line 61 by compressor 69 in proportions suicient to convert the aldehydes and ketones contained in the oxygenated feed into the corresponding alcohols. Reactor 65 contains a mass 66 of any conventional hydrogenation catalyst. Forv example, when nickel is employed as the hydrogenation catalyst, reactor 65 maybe operated at pressures ranging from about 300 to 3000 pounds per `square inch, at temperatures of about 200 to 400 F. and at a hydrogen feed of about 5000 to 15,000 normal cu. ft. per barrel of feed. The catalyst may be employed in the form of xed or moving beds or it may be suspended in the liquid feed. Details of hydrogenation processes of this type are well known in the art and need not be further specified. Unreacted hydrogen may be withdrawn overhead from reactor 65 through line 1l and either vented through line 13 or recycled through line 15 via lines 52 and/or 11 to the catalyst removal zone 50 as previously described or hydrogenation reactor 65. The hydrogenated product stream is withdrawn from reactor 65 through line 19 and may be passed to a separator 80 in which entrained gas may be separated from the liquid product. Hydrogen separated in separator 80 may be recycled through line 8l to hydrogen feed line 61. Final liquid alcohol product is withdrawn through line 83. It may be passed to any conventional product recovery system (not shown).

The system illustrated by the drawing permits of various modifications. Other conventional oxygenation catalysts than those specified may be supplied to line l. For example, insoluble finely divided metal catalysts may be used in aqueous or oil suspension. Instead of nickel other hydrogenation catalysts such as tungsten, or suliides of metals of groups VI and VIII of the periodic table may be utilized. Further modifications may occur to those skilled in the art without deviatlng from the spirit of the invention.

The superiority of the present invention over customary procedures will be further substantiated by the following experiments.

An oxygenated material was produced from olefins and synthesis gas as follows:

A diisobutylene feed containing 1% dissolved cobalt stearate and 4% C9 alcohol as a solubilizer for the catalyst was treated continuously with Hz-l-CO in the ratio of 1:1 at a pressure of 3000 lbs. per sq. in. gauge and at 300-315 F. reaction temperature in a reactor packed with 300 cc. of silica gel. The olefin feed was passed through the reactor at a rate of 'Z5-150 cc. per hour with synthesis gas introduced at an average rate of about 10,000 cu. ft/bbl. of olefin feed. The product from this operation contained 56.2 wt. per cent of oxygenated material and 43.8 wt. per cent of unconverted olefin.

To a portion of this oxygenated material there was added about 0.19 per cent by weight of ptertiary-butyl-catechol as a polymerization inhibitor. One sample of the original oxygenated product and a sample of the portion containing the p-tertiary-butyl catechol were separately distilled at atmospheric pressure. A-second sample of the original product was distilled at 10 mm. Hg pressure in accordance with the invention. The products from these three experiments were separately hydrogenated on nickel-on-kieselguhr catalyst containing about 60% Ni, at a temperature of 350 F., a pressure of 2700 pounds per l In presence of p-tertiary-butyl catechol.

The above data indicate that eflective suppression of C9 aldehyde condensation is accomplished by the reduced pressure distillation of the present invention, while distillation in the presence of a condensation inhibitor at normal pressure is not effective for the prevention of aldehyde condensation.

While the foregoing description and exemplary operations have served to illustrate specific applications and results of the invention, other modifications obvious to those skilled in the art are within the scope of theinvention. Only such limitations should be imposed on the invention as are indicated in the appended claims.

I claim:

l. In ,the production of oxygenated organic compounds by reacting oleiins with CO and H2 in an oxygenation zone at oxygenation conditions of temperature and pressure in the presence of 'an oxygenation catalyst the improvement which comprises withdrawing a mixture of oxygenated products and unconverted olefns from said oxygenation zone, distilling said mixture, in the presence of dissolved oxygenation catalyst and prior to further conversion, at a reduced pressure of about 5 to 500 mm. Hg adapted to separate unconverted olens from oxygenated products without excessive condensation of aldehydes and recycling said separated olefins to said oxygenation zone.

2. The process of claim 1 in which said oxygenated products after said reduced pressure distillation are hydrogenated at hydrogenation conditions of temperature and pressure and in the presence of a hydrogenation catalyst adapted to convert aldehydes and ketones into the corresponding alcohols.

3. The process of claim 1 in which said catalyst comprises the salt of a metal selected from the group of cobalt, iron and nickel with a high molecular weight fatty acid recovered from the liquid product of the catalytic synthesis of hydrocarbons from CO and H2.

4. The process of claim 1`in which said reduced pressure is substantially lower than said oxygenation pressure and said mixture is flashed from a zone maintained substantially at said oxygenation pressure and at a temperature not substantially below said oxygenation temperature into a distillation zone maintained at said reduced pressure so as to utilize the sensible heat of said mixture for its distillation in said distillation zone.

5. In the production of oxygenated organic compounds by reacting olens in the liquid state Awith CO and H2 in an oxygenation zone at oxygenation conditions of elevated temperatures and pressures in the presence of an oxygenation catalyst, the improvement which comprises withdrawing a. liquid mixture of oxygenated products and unconverted olens substantially aty said oxygenation temperature and pressure from said oxygenation zone, passingl said withdrawn mixture, in the presence of dissolved oxygenation catalyst and prior to further conversion, into a reduced-pressure distillation zone maintained at a reduced pressure of about to 500 mm. Hg and a temperature adapted to distill unconverted oletlns from liquid oxygenated products without excessive condensation of aldehydes, withdrawing olen vapors from said distillation zone, separately withdrawing liquid oxygenated product from said distillation zone, condensing said olen vapors, and returning said condensed oleiins to said oxygenation zone.

6. The process of claim 5 in which said withdrawn mixture is freed in a, separation zone of entrained gases, prior to being passed to said .distillation zone.

7. The process of claim 6 in which said separation zone is maintained at a temperature and pressure adapted to maintain unconverted oleflns in the liquid state.

s. The process of claim 5 in which said wich-`- drawn oxygenated product after said reduced pressure distillation is hydrogenated in the liquid state with a hydrogenating catalyst and at pressures and temperatures adapted to convert aldehydes present in said oxygenated product into the corresponding alcohols.

9. In the production of oxygenated organic compounds in a continuous process by reacting olens with CO and Ha in an oxygenation zone at oxygenation conditions of temperature and pressure in the presence of an oxygenation catalyst which catalyst dissolves at least in part in 8. the oxygenated product, removing the dissolved oxygenating catalyst from the oxygenated product, hydrogenating the so treated oxygenated product to form alcohols, and recovering the alcohols formed by distillation the improvement which comprises distilling the said oxygenated product, prior to said catalyst removal and hydrogenation,v at a reduced pressure of about 5 to 500 mm. Hg adapted to separate unconverted olefins from oxygenated products without excessive condensation of aldehydes and recycling said separated olens to said oxygenation zone.

PAUL T. PARKER..

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,151,106 Hentrich et al Mar. 21, 1939 2,153,526 4Walker Apr. 4, 1939 2,327,066 Roeien Aug'. 17, 1943 2,415,102 Landgraf et al Feb. 4, 1947 OTHER REFERENCES 

1. IN THE PRODUCTION OF OXYGENATED ORGANIC COMPOUNDS BY REACTING OLEFINS WITH CO AND HS IN AN OXYGENATION ZONE AT OXYGENATION CONDITIONS OF TEMPERATURE AND PRESSURE IN THE PRESENCE OF AN OXYGENATION CATALYST THE IMPROVEMENT WHICH COMPRISES WITHDRAWING A MIXTURE OF OXYGENATED PRODUCTS AND UNCONVERTED OLEFINS FROM SAID OXYGENATION ZONE, DISTILLING SAID MIXTURE, IN THE PRESENCE OF DISSOLVED OXYGENATION CATALYST AND PRIOR TO FURTHER CONVERSION, AT A REDUCED PRESSURE OF ABOUT 5 TO 500 MM. HG ADAPTED TO SEPARATE UNCONVERTED OLEFINS FROM OXYGENATED PRODUCTS WITHOUT EXCESSIVE CONDENSATION OF ALDEHYDES AND RECYCLING SAID SEPARATED OLEFINS TO SAID OXYGENATION ZONE. 